This invention relates to containers commonly used for food service, but could also be used to hold toys, repair parts, assembly parts and other small items. More specifically, this invention relates to the use of such containers and a means to hold them in a substantially full open condition, such as, but not limited to fast food clamshell containers used in carryout or drive-thru restaurants. Even more specifically, this invention creates a strong open tray from an otherwise hinged two-shell container which will structurally span between a seated user's upper thighs.
Clamshell containers are commonly used for serving food, such as fast-food hamburgers or chicken meals. The containers currently offered have various securing devices to keep them closed for serving and transporting the food. However, when they are opened for eating the food, provisions for keeping the containers open and not collapsing are necessary. When the material used for the container blank has an elastic memory, a problem occurs when the assembled open container tends to return to the previous closed position. Another common problem occurs when the open container is rested on a person's lap—which is often done by occupants of an automobile or truck after purchasing food through a drive-thru window. When the container is rested with one shell on one thigh and the other shell on the other thigh, the flexible container hinge, which connects the two shells, has a tendency to allow the two shells to rotate together causing the container to fall between the diner's legs when subjected to gravitational or other substantially vertical force; thus causing unintended full or partial closure of the container. This situation is particularly troublesome for young children—such as when two different foods are served on the opposite shells of the open container in a divided serving tray manner.
Clamshell containers are widely used to serve and transport fast food, carry out meals, box lunches, and leftover portions of meals. Similar containers can also be used to contain toys, puzzle parts, repair parts, assembly parts, craft parts, and so on. At times the users will desire to access the contents of the container when the user is in a seated position, such as but not limited to sitting in the seat of a vehicle. In some occasions, it is desired for the two container shells to be supported by the user's upper thighs. In those occasions, it is often desirable for the two container shells to remain in an open position, and resistant to the tendency of closure of the container, particularly when subjected to substantially perpendicular gravitational or user induced forces. It is common to use containers with two container shells which are foldably interconnected, commonly known as clamshell containers. There are various existing designs of clamshell containers which incorporate features to secure the container in a closed position. U.S. Pat. No. 4,232,816 to Johnson et al and U.S. Pat. No. 6,283,364 to Gray Sr. describe examples of clamshell containers that incorporate a means for securing the containers in the closed position. However, most existing containers suffer from a lack of means to secure them in an open position.
U.S. Pat. No. 5,538,179 to Cai provides a means to secure the shells in the open position, but suffers from an inherently weak securing design, which is dependant on the flexural strength of the inner walls of the shells. Further, this design suffers from an inherently weakened and severed hinge which connects the two shells, thus reducing the structural strength necessary to span the lateral direction of the open container shells. Finally, this design is limited in that it is dependant on a container shell geometry which provides for direct contact between the two inner walls of the open container shells, thus precluding this design to be applicable to sloped inner wall shell designs which do not contact each other when the container is opened to approximately one hundred and eighty degrees from the closed condition.
U.S. Pat. No. 5,826,784 to Wojcik overcomes the deficiencies described herein for Cai's design. However, this design suffers from the requirement to incorporate additional secondary material over what is required for the fabrication of the container itself, absent the securing device. This requires additional material and labor expense, complexity in manufacturing, and increases the amount of the resulting waste when the container is ultimately discarded. Further, this design suffers from requiring the user to blindly or awkwardly manipulate the tape latching device to the bottom of the open container shell, which may be challenging for certain users, such as young children or elderly adults.